In the field of Supply Chain Management, traditional systems have relied upon stored data to define the availability of either the item to be ordered or of the immediate items that make up the item to be ordered. The stored data that defines the availability of items has been either an accounting of available inventory, or a combination of accounted-for inventory and tracked replenishments on order. Furthermore, previous systems have relied upon other systems to periodically update the item availability information. Such an approach, utilized by previous systems, presents several problems. For example, some systems only operate for orders of items that are expected to be ordered and treat the availability of all resources in the same manner, i.e. the availability of materials treated in the same manner as the availability of capacity. However, the various types of resources are quite different with respect to their availability, either temporarily or permanently. While materials, unused in a given period, are generally available in any subsequent period, unused capacity in a given period is usually not available in any subsequent period. For these systems to determine the availability of items for a new request, availability information for supplies of that item and its immediate components, if any, must be available, together with availability information for the capacity constraints. Provided that both current and relevant information is available, the system is able to make a determination with respect to the availability of the item. Otherwise, such systems are flawed, as they are reliant on regular updates of item availability information.
Other supply chain management systems determine item availability by developing a detailed production schedule for the needed items, while respecting existing commitments for supplying items. These systems, commonly known in the art as finite capacity schedulers, require excessive computing resources and time to generate a new schedule for each changed supply or demand. The excessive computation times are problematic in business environments where businesses are required to provide completion or delivery dates in a timely manner for interactive purposes.
More recent prior art has addressed the processing time inherent in updating plans. They use two processes. The first process generates an entire plan from the initial data. The second process accepts a small number of changes and replans or repairs the plan around those data changes. The intention being that the processing time to repair a plan after accepting a limited number of changes is much less than the processing time required to generate a new plan from the entire data set.
The present invention (1) reduces the complexity of the calculations and (2) manages storage of intermediate results so that new plans can be generated whenever data changes.
Supply Chain Management concepts underlie many types of business environments, such as manufacturing environments, distribution environments and business organization environments. Each business environment generally has a supply structure producing various items. The prior art systems utilize the supply structure to map out a completion or delivery date for demand and supplies in these business environments. In a manufacturing environment an item is produced, for example, by applying processes to components. The components themselves may also be made from processes and subcomponents, resulting in several layers of process and components needed to make the item. These layers of processes, components and subcomponents form the supply structure for the item. These systems use the principles of netting and explosion to determine a completion or delivery date for the demand. These principles are further elaborated upon in “Material Requirements Planning: The New Way of Life in Production and Inventory Management”, by Joseph A. Orlicky, N.Y.: The McGraw-Hill Companies, 1974.
In the prior art, however, current supply chain management does not incorporate capacity constraints when determining completion or delivery dates for requested demands. What is needed therefore is a method of determining promise dates for an item having at least one capacity constraint where the availability of supplies for a given item are not known in advance. What are further needed are a method and a system where the promised delivery date of a demand is determined in an expedited manner without adversely affecting the promise dates of existing commitments for items.